Contents of the UARTMON.DOC file

This program is designed to monitor the UARTS associated with serial ports ( COM1-COM4 ). It is intended to be use simultaneous with an application using the UART. It should not interfere in the monitoring mode although the menus allow the end user to change the baud rate, data_bits, stop_bits, and parity. Certain combinations of data_bits, stop_bits, and parity are not valid and are inhibited in the menus. Because the intended use is to monitor the serial port the serial ports are not opened and the interrupts of are not modified, tested, or chained. If no application is using the UART then the monitor will not reflect valid information ( i.e. the UART needs to be initialized by an application other than the monitor. )

PRINCIPLE:

In the BIOS DATA AREA of system memory there is a list of serial port addresses in the 4 words beginning at 0000:0400. Most systems use the default 3F8 for COM1 and 2F8 for COM2. There is no standard for COM3 and COM4, so you need to make sure the BIOS DATA AREA correctly reflects the right addresses for COM3 and COM4 if your machine has these ports. Windows uses default addresses as listsed below but these can be altered using the COMxBase=XXXh directive in the SYSTEM.INI file. ( see SYSINI2.TXT in you {WINDOWS} directory).

If you encounter any problems with accessing serial ports it would be a good idea to verify the addresses stored in the BIOS DATA AREA. This can be accomplished using the "Ports" menu. There is an option IO_Address which shows the IO_Address as determined from WINDOWS default setting or values that are read from the BIOS. If a COMx address shows "default" as the source then the BIOS does not know the address. It is still possible that software (including WINDOWS APPS...) can function if it is written to bypass the BIOS DATA AREA values for the UART IO address. If a COMx address shows the source as bios then the value for that port was determined from a read of the BIOS DATA AREA.

Once the IO address is known for a given UART it is a simple task to investigate the UART registers to determine the status of the various RS232 lines. The monitor gets a WM_TIMER message every 200 msecs and update the screen with any changes in the UART status.

As a utility this can be very useful when first connecting a new serial device. Basically this is a WINDOWS "BREAKOUT Box".

HOW TO USE THE PROGRAM:

Just run it and read the results.

DISTRIBUTION:

UARTMON.EXE and this document are provided free by Unitech Associates, Inc., Newark, Delaware. They may be copied and distributed provided no money is charged for them and they are not modified. Although the program has been extensively tested, Unitech Associates, Inc. provides no warranty concerning its usefulness on all systems and UA, Inc. accepts no responsibility or liability for any mishap resulting from its use.